(a) Field of the Invention
This application relates to a safety helmet assembly, such as a fireman's helmet, and more particularly to an improved head band and chinstrap assembly for positioning, adjusting and securing the protective helmet assembly onto the head of the user.
(b) Description of the Prior Art
For the longest time, firefighters and other protective helmet users were given their protective helmets, accomplished an adjustment to make them feel comfortable, and then wore them exclusively, with no trading around or passing off of one person's helmet to another. While this is still virtually true in the municipal firefighting business, and with individual hard-hat users who own and maintain their own head protection, it is not typical in industrial fire brigades where the equipment, head to toe, is shared between several different people without really much thought for proper adjustment, or perfect fit. Because of the time pressure, and the need for universal fit, commonly the helmets are worn with their suspensions wide open, very loosely fitting. When a user wears such a helmet, he depends entirely on the chinstrap to hold the helmet on his head, and this is only modestly effective in retaining the helmet on the user's head when he is in precarious or exposed circumstances.
Currently, the protective helmet assemblies are primarily dominated by head adjustment systems that are individually accomplished by each wearer/owner. The most popular version of such fixed adjustment suspension system employs a post and hole, single adjustment, with the adjustment accomplished at the sides or at the rear. A ratchet system and alternately a breakaway feature allow more flexibility and adjustability on a quick-release basis, should the wearer change the protective equipment he is wearing under the suspension system, and needs to change the sizing to fit the helmet properly on his head. Such breakaway feature is a fixed one, however, and does not refit the helmet, but simply opens it up generally, allowing for the increase in sizing caused by donning the breathing apparatus face piece, a knit hood, or both.
Such ratchet system has a turning knob that mounts at the rear of the head, under the helmet and suspension system. It is exposed well outside the protective envelope of the helmet, but does provide reasonably comfortable and effective instant adjustment, no matter what kind of equipment layering is going on underneath the head suspension system in the helmet. The ratchet system poses the very present danger of being exposed to direct impact, and focusing impact energies in transferring that impact to the user's head. Any adjustability feature of the ratchet system has been deemed so important with the changes in head sizing caused by donning and doffing the various new layers of protection common to the fire service, that people have decided to overlook the potential danger of "on-ratchet" impact in deference to the importance of proper fit. In addition, in an emergency situation, the complexity of any adjustment mechanism slows down the donning procedure, and if it is too time consuming or inconvenient, will actually not even be used before the wearer exposes himself to circumstances and conditions which might require the proper retention of his helmet on his head.